Content Warning: This section of the guide includes discussion of religious discrimination, graphic violence, bullying, illness and death, and physical abuse.

The black moths in the story are a symbol of evil and hate. They represent how hatred can infiltrate and spread throughout groups, sometimes before it can be recognized.

Initially, only Anne can see the moths; for example, one appears the day before the German invasion. This moth foreshadows the coming danger and establishes a mood of ominous doom. Additional moths arrive as Anne realizes that her parents are afraid of Germany’s power, the ongoing effects of war, and the outcomes of hatred against Jewish people. Later, other people like passersby on the sidewalks sense the presence of the moths and try to stay out of their way. These moths appear in corners and along edges of places, as if ghostlike or illusory. Anne tries to keep from worrying about the moths but realizes they cannot be ignored; in the same way, the persecution of the Jewish people eventually cannot be ignored, prompting many to flee or hide.

Margot thinks she sees a black moth on the day she turns 16; this moth represents the spreading evil in their world.